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Biomedical subjects

L M Hansen

Publications and source records attributed to L M Hansen.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cloning and sequence of the groESL heat-shock operon of Pasteurella multocida.

By using degenerate oligodeoxyribonucleotide primers for conserved regions of groEL, a 0.6-kb fragment of Pasteurella multocida genomic DNA was amplified using PCR. The amplified fragment was then used as a probe to isolate a genomic fragment containing the entire GroESL operon. The isolated genomic fragment was found to contain two open reading frames, the sequences of which were highly homologous to the prokaryotic groES and groEL families of genes.

Amino Acid Sequence↗
PubMed1995

Pasteurella multocida produces a protein with homology to the P6 outer membrane protein of Haemophilus influenzae.

An antibody specific for a 16-kDa outer membrane protein of a rabbit strain of Pasteurella multocida was used to probe representatives of all 16 somatic serotypes of P. multocida, as well as the vaccine strains CU and M9, and all were shown to express the protein. The gene encoding this protein was cloned and sequenced and found to have extensive sequence homology with the gene encoding the P6 protein of Haemophilus influenzae. The protein in P. multocida has been designated P6-like. The gene encoding the P6-like protein was used to probe members of the family Pasteurellaceae and other gram-negative bacteria. Representatives of all 16 somatic serotypes (as well as the vaccine strains CU and M9) of P. multocida hybridized with the P6-like gene under conditions of high stringency. The DNA from H. influenzae hybridized weakly with the P6-like gene under these conditions, but Pasteurella haemolytica (representatives of A and T biotypes), Bordetella bronchiseptica, B. avium, Actinobacillus suis, A. suis-like, A. lignieresii, A. ureae, A. rossii, A. pleuropneumoniae, A. equuli, and various members of the family Enterobacteriaceae (Escherichia coli, Klebsiella pneumoniae, and Salmonella typhimurium) did not hybridize detectably. Under conditions of lower stringency, the P6-like gene also hybridized strongly with DNA from P. multocida, H. influenzae, and A. rossii but weakly with DNA from P. haemolytica and members of the genus Actinobacillus. These results suggest that the P6-like protein of P. multocida might be useful as an immunizing product to protect poultry from avian cholera. This suggestion stems from (i) our finding that the P6-like protein in P. multocida is widely distributed among all the somatic serotypes and (ii) the previous work of others demonstrating that the P6 protein of H. influenzae elicits a protective immune response in animal models of human disease.

Amino Acid Sequence↗
PubMed1994

[Neuropathy in adult metachromatic leukodystrophy].

Metachromatic leukodystrophy is a rare autosomal recessive disorder with deficient arylsulphatase A activity. Different forms occur according to the age at onset of symptoms. Adult forms generally present with presenile dementia and/or psychiatric symptoms. We report a case of a 45-year-old woman, without a family history of neuropsychiatric disorders, presenting with complaints of numbness and weakness of the lower limbs. No intellectual or behavioral disturbances were clinically detectable. Electrophysiological investigation was compatible with severe demyelinating neuropathy in upper and lower limbs. MRI of the brain showed multiple white matter lesions. Adult metachromatic leukodystrophy was diagnosed on the basis of low leucocyte arylsulfatase-A-activity and accumulation of metachromatic material in the sural nerve. Pseudo-deficiency was excluded by DNA analysis. This case indicates that adult metachromatic leukodystrophy should be considered in patients with symptoms and signs resembling multiple sclerosis with peripheral neuropathy and in patients with neuropathy of unknown etiology.

Brain Diseases↗
PubMed1993

A new tetracycline resistance determinant, Tet H, from Pasteurella multocida specifying active efflux of tetracycline.

The tetracycline resistance determinant on plasmid pVM111 from an avian strain of Pasteurella multocida mediates tetracycline resistance by a regulated active efflux mechanism. DNA coding for the determinant did not hybridize at high stringency with DNA representing a group of common tetracycline resistance determinants. The DNA sequence, however; revealed a structural gene and a repressor gene which had significant (37 to 64%) sequence similarities with previously described classes of efflux-type tetracycline resistance genes from members of the family Enterobacteriaceae. The new determinant has been assigned to class H.

Amino Acid Sequence↗
PubMed1993

Use of random fragments of chromosomal DNA to highlight restriction site heterogeneity for fingerprinting isolates of Salmonella typhimurium from hospitalized animals.

Random fragments of DNA were obtained from a cosmid library of Salmonella agona genomic DNA. From this library, 2 fragments were chosen and pooled to probe isolates of S typhimurium obtained during an episode of salmonellosis in a veterinary medical teaching hospital. Chromosomal DNA from the Salmonella isolates was digested with restriction endonucleases, and was probed with the random fragments of chromosomal DNA. This procedure resulted in a fingerprint pattern for each isolate. We found that the method permitted discrimination between isolates involved in the disease episode and S typhimurium obtained prior to the episode. We conclude that random fragments of chromosomal DNA are useful for fingerprinting isolates of S typhimurium. Analysis of plasmid DNA obtained from the isolates was not as useful. Some isolates found to be identical by restriction site analysis, had plasmids of different molecular weight. These results indicate that plasmid analysis may not be as useful a fingerprinting tool as previously reported.

Animals↗
PubMed1992

[Leptospirosis. A disease with non-specific initial symptoms].

A case of leptospirosis in a young fish-farm worker is described. Early penicillin therapy was initiated solely on the clinical suspicion of the disease. The importance of recognition of the disease is emphasized together with early institution of penicillin therapy and effective eradication of vermin.

Adult↗
PubMed1989

[Knowledge of AIDS and of transmission risks of HIV infection in a group of homosexual people. A questionnaire study].

A questionnaire investigation among 430 homosexual persons all of whom were members of an organization for homosexuals was completed by 144 (33%). These replies showed that they knew about HIV infection, risk behaviour and "safe sex". Their knowledge about the signs of HIV infection and AIDS was, however, more limited. The replies were compared with an age-matched group of the male population. The results of the investigation provide reasons to suppose that the information campaigns have been of value but information to prevent spread of infection is still necessary. In addition, further information is necessary about the subjective signs of HIV-infection so that persons in whom these signs develop may be offered the best possible treatment as early as possible.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[A group of homosexuals change their sex habits after information about AIDS. A questionnaire survey].

A questionnaire investigation to which 144 homosexual persons replied anonomously revealed alterations in the sexual habits after information about AIDS. Significant reduction in the annual number of partners and significantly fewer employ the more dangerous sexual practices which now occur particularly in more permanent partnerships are among the alterations started. An unchanged number still employ active anal and orogenital coitus. Employment of condoms has increased significantly, particularly in anal coitus and "casual" partners (from 3% to 82%). The majority accept the use of condoms and state that they employ more "safe sex" than prior to information about AIDS. 12% stated that they had sex with both sexes and the possibility of spread of infection from homosexual to heterosexual groups is present. The intensive informative work from the homosexuals own organisation and from public health authorities appear to have had some effect but further information and influencing are necessary if the spread of HIV infection is to be stopped.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Serum resistance is correlated with encapsulation of avian strains of Pasteurella multocida.

Encapsulated avian strains of Pasteurella multocida possessing an A-type capsule were shown to be resistant to the bactericidal action of turkey serum, whereas unencapsulated variants as well as other unencapsulated strains were not. Removal of the capsule from serum-resistant strain P1059-1 resulted in this strain becoming susceptible to the bactericidal effects of turkey serum. Since complement was consumed when encapsulated or unencapsulated strain P1059-1 was incubated in turkey serum, we conclude that the capsule acts to shield the outer membrane rather than prohibiting the generation of an effective membrane attack complex.

Animals↗
PubMed1989

Resistance to antimicrobial agents and prevalence of R plasmids in Pasteurella multocida from turkeys.

One hundred fifty-three isolates of Pasteurella multocida, representing the causative agent of 95% of all known outbreaks of fowl cholera occurring in California meat and breeder turkeys from August 1985 through February 1987, were examined for susceptibility to antimicrobial agents. Of the 153 isolates, 6 were shown to be resistant to one or more antimicrobial agents. Of the six resistant isolates, five contained R plasmids. All but one of the R plasmids were small (6 to 7 megadaltons) and nonconjugative, encoding resistance to tetracycline or kanamycin, streptomycin, and sulfonamides; the other was large (70 megadaltons) and conjugative, transferring resistance to kanamycin, streptomycin, sulfonamides, and tetracycline to P. multocida and Escherichia coli. The three plasmids encoding resistance to tetracycline alone appeared identical.

Animals↗
PubMed1989

Use of an rRNA probe and restriction endonuclease analysis to fingerprint Pasteurella multocida isolated from turkeys and wildlife.

Twenty-five isolates of the bacterium Pasteurella multocida were characterized (fingerprinted) phenotypically and genotypically in order to compare the abilities of various techniques to differentiate strains for epidemiologic studies of fowl cholera. Isolates were obtained over a 16-month period from turkeys dying from fowl cholera (six outbreak flocks) and from wildlife captured on premises with a history of the disease. The characteristics compared included (i) serotype, (ii) subspecies, (iii) antibiogram, (iv) presence of plasmid DNA, (v) restriction endonuclease analysis patterns of whole-cell DNA, and (vi) ribotype. Ribotyping, a method of highlighting DNA restriction site heterogeneity by using an rRNA probe, worked well for differentiating the strains of P. multocida when the majority of the other techniques could not. Ribotyping results correlated directly with and confirmed results obtained from restriction endonuclease analysis. Ribotyping demonstrated the presence of up to three strains of P. multocida in one outbreak flock, recurrence of a single strain in five of the flocks over an 11-month period, and the presence of common strains in turkeys and wildlife on the premises.

Animals↗
PubMed1988

Plasma- and iron-regulated expression of high molecular weight outer membrane proteins by Pasteurella multocida.

A strain of Pasteurella multocida of avian origin expressed high molecular weight outer membrane proteins when grown in turkey plasma or in brain-heart infusion broth containing the iron chelator dipyridyl. The proteins were not detected when this strain was grown in brain-heart infusion broth or in brain-heart infusion broth containing dipyridyl and excess iron.

2,2'-Dipyridyl↗
PubMed1984

An outbreak of diarrhoea in hoggets associated with infection by Yersinia enterocolitica.

An outbreak of diarrhoea in a flock of 450 Romney hoggets was investigated. The flock was receiving suboptimal pasture allowance on an intensive 4-day controlled grazing rotation. Approximately 30% were affected with a foul-smelling diarrhoea and four died. Yersinia enterocolitica was isolated from small and large intestines of three affected sheep. Organisms consistent in appearance with Yersinia spp. were demonstrated in suppurative foci in the lamina propria of the small and large intestines. Affected animals were removed from the mob and appeared to respond clinically to tetracycline therapy. The outbreak lasted about two weeks.

Journal Article↗
PubMed1984

Presenting symptoms and treatment delay in osteosarcoma and Ewing's sarcoma.

Presenting symptoms and treatment delay were investigated in a series of 84 osteosarcomas and 40 Ewing's sarcomas. The treatment delay averaged 6.4 months for osteosarcomas and 9.6 months for Ewing's sarcomas. In both types the delay was relatively short in patients with constant pain and swelling. The prognosis was about the same whether the delay was short or long. This may be explained by the more severe nature of the presenting symptoms, in particular the constant pain and swelling, in aggressive tumours, a factor that also tends to mask other relevant prognostic parameters. It is concluded that the presenting symptoms and the treatment delay constitute important pathophysiologic factors which should be given more attention when analysing material from bone sarcomas.

Adolescent↗